Underhammer Barrel Marks?

Can someone explain these numbers on the bottom of this underhammer rifle. It is a Remington barrel. I have looked online and in books and have not found an explanation or even seen pics of others like it. I am only assuming that it is related to the rifling...and that the second set of numbers...might be the rate of twist? I am including a full length pic of the rifle...just because....nobody...myself included likes it when that is left out.

Nice UH, do you know who built it? Sorry, I can't help you with the numbers but Remington was a major supplier of barrels to the muzzleloading trade.

barrel width and 1 turn in 74 inches possible

It appears to have a muzzle turned for a starter, and otherwise looks like a target rifle. It is likely that it is intended for a picket bullet, and may have gain twist rifling - which would make sense with a pitch stated in feet, beginning with 1-72" (6 feet) and ending with 1-24" (2 feet). If you drop a bore light down the bore, a gain twist should be apparent. And the 1 1/4" is probably (as already said) the barrel diameter across the flats.
Check it out!

mhb - Mike

MHB...thanks...I believe you are right...though I must admit it took some thought for me to figure out exactly what you were talking about. The gain twist is something that I have heard of but wasn't exactly sure what it was. Interesting that it would be marked in feet like that....I never would have figured that out on my own. Question: why would you bother to mark the barrel with the rate of twist/gain twist....would it benefit the shooter in some way to know?
Also: as you can see from the photo added it seems close to 1 1/4 inches across the barrel flat...though the false muzzle makes it a bit hard to measure exactly.
As to who made this rifle...I wish I knew. The Remington mark on the barrel is well worn...and was probably only saved by being underneath the rear peep sight. The makers mark...if it ever did have one...may very well have been worn off. It does seem to closely resemble the works or Story, Kendall, and Hilliard.....but I don't know how you would tell for sure which one made it...if any of them. I would be happy to hear any thoughts concerning that.

Initially it doesn't look like it is an A. Story gun. The trigger guard is unlike any I have seen and there aren't many surviving Storys. The hammer is somewhat similar but different from my Story too. Close ups of the inlays under the action screws might help as these sometimes were quite distinctive. Photos of the hammer and rear sight and its method of adjustment may help identify the gun too. The more I see of your gun the better I like it.

Sorry if I caused some confusion: I should have referred back to the marking itself - '6-2'. And this, too, is speculation on my part (but not a wild guess). Is the rifling obviously gaining pitch?
Barrel makers often mark their products with specific technical information, both for their own records and for the owner of the piece: knowing what the final pitch was, in a gain twist barrel, would help the user to determine what weight bullet would likely work best. Harry Pope, among others, marked his barrels with such information.
The muzzle of your rifle is turned round not for a false muzzle, which would have had pins in the false muzzle itself and corresponding holes in the muzzle, but for a straight starter, used to properly seat the picket bullet and cloth patch; as was necessary to insure that the picket, which had little or no parallel body, was centered properly in the bore and not 'cocked' with the long axis of the bullet not coinciding with the centerline of the bore.
Yours appears to be a really nice rifle, and, I hope, in shootable shape.
FWIW, you should be able to measure the barrel across the flats with a simple caliper, or even with a ruler by eyeball.

mhb - Mike

Thanks for the clarification around the false muzzle/ turned barrel. I don't have a light to drop down the barrel to check it...but I would bet dollars to donuts that you are right...and it is a gain twist. I will check it at some point. Based upon your information I researched picket rifles/ picket bullets/ gain twist aka "creedmore". Pretty interesting stuff. The rifle is in quite good condition...and what I can see of the rifling appears to be good...no snags in the barrel near the breech.
Here are some close up picks of some of the various features....let me know if you recognize similarities to any particular maker.

That really is a nice rifle. The wood is beautiful.
One thing that strikes me as unusual for what is almost certainly a rifle intended for target shooting, specifically, is that it appears to have a simple, rather than a set trigger.
The maker should certainly have signed it - it's worthy of his signature.
Let us know what else you may learn about it.

mhb - Mike

With the trigger directly engaging the notch in the hammer and the lack of intervening parts it is possible to get an exceptionally fine trigger in an underhammer. Set triggers are extremely rare in original underhammers, almost to the point of having never been done. Having said that I'm sure someone will come up with an example but I have never seen one. I'm excluding 20th. century guns built for Friendship.